ruby 版本:ruby-1.9.3-p545 [ x86_64 ] 启动服务器的时候 rails s 报错,什么原因?
chenc@ubuntu:~/gcj_project/gcj_project/ruby-china$ rails s
=> Booting Thin
=> Rails 4.1.1 application starting in development on http://0.0.0.0:3000
=> Run `rails server -h` for more startup options
=> Notice: server is listening on all interfaces (0.0.0.0). Consider using 127.0.0.1 (--binding option)
=> Ctrl-C to shutdown server
Exiting
/home/chenc/.rvm/rubies/ruby-1.9.3-p545/lib/ruby/1.9.1/psych/visitors/to_ruby.rb:264:in `merge!': can't convert nil into Hash (TypeError)
from /home/chenc/.rvm/rubies/ruby-1.9.3-p545/lib/ruby/1.9.1/psych/visitors/to_ruby.rb:264:in `block in revive_hash'
from /home/chenc/.rvm/rubies/ruby-1.9.3-p545/lib/ruby/1.9.1/psych/visitors/to_ruby.rb:258:in `each'
from /home/chenc/.rvm/rubies/ruby-1.9.3-p545/lib/ruby/1.9.1/psych/visitors/to_ruby.rb:258:in `each_slice'
from /home/chenc/.rvm/rubies/ruby-1.9.3-p545/lib/ruby/1.9.1/psych/visitors/to_ruby.rb:258:in `revive_hash'
from /home/chenc/.rvm/rubies/ruby-1.9.3-p545/lib/ruby/1.9.1/psych/visitors/to_ruby.rb:141:in `visit_Psych_Nodes_Mapping'
from /home/chenc/.rvm/rubies/ruby-1.9.3-p545/lib/ruby/1.9.1/psych/visitors/visitor.rb:15:in `visit'
from /home/chenc/.rvm/rubies/ruby-1.9.3-p545/lib/ruby/1.9.1/psych/visitors/visitor.rb:5:in `accept'
from /home/chenc/.rvm/rubies/ruby-1.9.3-p545/lib/ruby/1.9.1/psych/visitors/to_ruby.rb:20:in `accept'
from /home/chenc/.rvm/rubies/ruby-1.9.3-p545/lib/ruby/1.9.1/psych/visitors/to_ruby.rb:273:in `block in revive_hash'
from /home/chenc/.rvm/rubies/ruby-1.9.3-p545/lib/ruby/1.9.1/psych/visitors/to_ruby.rb:258:in `each'
from /home/chenc/.rvm/rubies/ruby-1.9.3-p545/lib/ruby/1.9.1/psych/visitors/to_ruby.rb:258:in `each_slice'
from /home/chenc/.rvm/rubies/ruby-1.9.3-p545/lib/ruby/1.9.1/psych/visitors/to_ruby.rb:258:in `revive_hash'
from /home/chenc/.rvm/rubies/ruby-1.9.3-p545/lib/ruby/1.9.1/psych/visitors/to_ruby.rb:141:in `visit_Psych_Nodes_Mapping'
from /home/chenc/.rvm/rubies/ruby-1.9.3-p545/lib/ruby/1.9.1/psych/visitors/visitor.rb:15:in `visit'
from /home/chenc/.rvm/rubies/ruby-1.9.3-p545/lib/ruby/1.9.1/psych/visitors/visitor.rb:5:in `accept'
from /home/chenc/.rvm/rubies/ruby-1.9.3-p545/lib/ruby/1.9.1/psych/visitors/to_ruby.rb:20:in `accept'
from /home/chenc/.rvm/rubies/ruby-1.9.3-p545/lib/ruby/1.9.1/psych/visitors/to_ruby.rb:238:in `visit_Psych_Nodes_Document'
from /home/chenc/.rvm/rubies/ruby-1.9.3-p545/lib/ruby/1.9.1/psych/visitors/visitor.rb:15:in `visit'
from /home/chenc/.rvm/rubies/ruby-1.9.3-p545/lib/ruby/1.9.1/psych/visitors/visitor.rb:5:in `accept'
from /home/chenc/.rvm/rubies/ruby-1.9.3-p545/lib/ruby/1.9.1/psych/visitors/to_ruby.rb:20:in `accept'
from /home/chenc/.rvm/rubies/ruby-1.9.3-p545/lib/ruby/1.9.1/psych/nodes/node.rb:35:in `to_ruby'
from /home/chenc/.rvm/rubies/ruby-1.9.3-p545/lib/ruby/1.9.1/psych.rb:128:in `load'
from /home/chenc/.rvm/gems/ruby-1.9.3-p545/bundler/gems/mongoid-da35e0cd0fc1/lib/mongoid/config/environment.rb:40:in `load_yaml'
from /home/chenc/.rvm/gems/ruby-1.9.3-p545/bundler/gems/mongoid-da35e0cd0fc1/lib/mongoid/config.rb:83:in `load!'
from /home/chenc/.rvm/gems/ruby-1.9.3-p545/bundler/gems/mongoid-da35e0cd0fc1/lib/mongoid.rb:98:in `load!'
from /home/chenc/.rvm/gems/ruby-1.9.3-p545/bundler/gems/mongoid-da35e0cd0fc1/lib/mongoid/railtie.rb:75:in `block in <class:Railtie>'
from /home/chenc/.rvm/gems/ruby-1.9.3-p545/gems/railties-4.1.1/lib/rails/initializable.rb:30:in `instance_exec'
from /home/chenc/.rvm/gems/ruby-1.9.3-p545/gems/railties-4.1.1/lib/rails/initializable.rb:30:in `run'
from /home/chenc/.rvm/gems/ruby-1.9.3-p545/gems/railties-4.1.1/lib/rails/initializable.rb:55:in `block in run_initializers'
from /home/chenc/.rvm/rubies/ruby-1.9.3-p545/lib/ruby/1.9.1/tsort.rb:150:in `block in tsort_each'
from /home/chenc/.rvm/rubies/ruby-1.9.3-p545/lib/ruby/1.9.1/tsort.rb:183:in `block (2 levels) in each_strongly_connected_component'
from /home/chenc/.rvm/rubies/ruby-1.9.3-p545/lib/ruby/1.9.1/tsort.rb:219:in `each_strongly_connected_component_from'
from /home/chenc/.rvm/rubies/ruby-1.9.3-p545/lib/ruby/1.9.1/tsort.rb:182:in `block in each_strongly_connected_component'
from /home/chenc/.rvm/rubies/ruby-1.9.3-p545/lib/ruby/1.9.1/tsort.rb:180:in `each'
from /home/chenc/.rvm/rubies/ruby-1.9.3-p545/lib/ruby/1.9.1/tsort.rb:180:in `each_strongly_connected_component'
from /home/chenc/.rvm/rubies/ruby-1.9.3-p545/lib/ruby/1.9.1/tsort.rb:148:in `tsort_each'
from /home/chenc/.rvm/gems/ruby-1.9.3-p545/gems/railties-4.1.1/lib/rails/initializable.rb:54:in `run_initializers'
from /home/chenc/.rvm/gems/ruby-1.9.3-p545/gems/railties-4.1.1/lib/rails/application.rb:288:in `initialize!'
from /home/chenc/gcj_project/gcj_project/ruby-china/config/environment.rb:6:in `<top (required)>'
from /home/chenc/.rvm/gems/ruby-1.9.3-p545/gems/activesupport-4.1.1/lib/active_support/dependencies.rb:247:in `require'
from /home/chenc/.rvm/gems/ruby-1.9.3-p545/gems/activesupport-4.1.1/lib/active_support/dependencies.rb:247:in `block in require'
from /home/chenc/.rvm/gems/ruby-1.9.3-p545/gems/activesupport-4.1.1/lib/active_support/dependencies.rb:232:in `load_dependency'
from /home/chenc/.rvm/gems/ruby-1.9.3-p545/gems/activesupport-4.1.1/lib/active_support/dependencies.rb:247:in `require'
from /home/chenc/gcj_project/gcj_project/ruby-china/config.ru:3:in `block in <main>'
from /home/chenc/.rvm/gems/ruby-1.9.3-p545/gems/rack-1.5.2/lib/rack/builder.rb:55:in `instance_eval'
from /home/chenc/.rvm/gems/ruby-1.9.3-p545/gems/rack-1.5.2/lib/rack/builder.rb:55:in `initialize'
from /home/chenc/gcj_project/gcj_project/ruby-china/config.ru:in `new'
from /home/chenc/gcj_project/gcj_project/ruby-china/config.ru:in `<main>'
from /home/chenc/.rvm/gems/ruby-1.9.3-p545/gems/rack-1.5.2/lib/rack/builder.rb:49:in `eval'
from /home/chenc/.rvm/gems/ruby-1.9.3-p545/gems/rack-1.5.2/lib/rack/builder.rb:49:in `new_from_string'
from /home/chenc/.rvm/gems/ruby-1.9.3-p545/gems/rack-1.5.2/lib/rack/builder.rb:40:in `parse_file'
from /home/chenc/.rvm/gems/ruby-1.9.3-p545/gems/rack-1.5.2/lib/rack/server.rb:277:in `build_app_and_options_from_config'
from /home/chenc/.rvm/gems/ruby-1.9.3-p545/gems/rack-1.5.2/lib/rack/server.rb:199:in `app'
from /home/chenc/.rvm/gems/ruby-1.9.3-p545/gems/railties-4.1.1/lib/rails/commands/server.rb:50:in `app'
from /home/chenc/.rvm/gems/ruby-1.9.3-p545/gems/rack-1.5.2/lib/rack/server.rb:314:in `wrapped_app'
from /home/chenc/.rvm/gems/ruby-1.9.3-p545/gems/railties-4.1.1/lib/rails/commands/server.rb:130:in `log_to_stdout'
from /home/chenc/.rvm/gems/ruby-1.9.3-p545/gems/railties-4.1.1/lib/rails/commands/server.rb:67:in `start'
from /home/chenc/.rvm/gems/ruby-1.9.3-p545/gems/railties-4.1.1/lib/rails/commands/commands_tasks.rb:81:in `block in server'
from /home/chenc/.rvm/gems/ruby-1.9.3-p545/gems/railties-4.1.1/lib/rails/commands/commands_tasks.rb:76:in `tap'
from /home/chenc/.rvm/gems/ruby-1.9.3-p545/gems/railties-4.1.1/lib/rails/commands/commands_tasks.rb:76:in `server'
from /home/chenc/.rvm/gems/ruby-1.9.3-p545/gems/railties-4.1.1/lib/rails/commands/commands_tasks.rb:40:in `run_command!'
from /home/chenc/.rvm/gems/ruby-1.9.3-p545/gems/railties-4.1.1/lib/rails/commands.rb:17:in `<top (required)>'
from script/rails:6:in `require'
from script/rails:6:in `<main>'